- a cardinal number represented in the U.S. by 1 followed by 9 zeros, and in Great Britain by 1 followed by 12 zeros.
- a very large number: I've told you so billions of times.
- equal in number to a billion.
Origin of billion
Examples from the Web for billionth
The temperature of Cygnus X-1 from Hawking radiation is roughly a billionth of a degree above absolute zero.Black Holes Exist. So Does Bad Science
Matthew R. Francis
September 28, 2014
We've moved from computers with a trillionth of the power of a human brain to computers with a billionth of the power.The Robots Are Coming!
May 14, 2013
We may be cousins to the worm, at the billionth remove; but we are not brothers.The Color Line
William Benjamin Smith
The vibrations which thus occasion light are, at a mean, 555 in the billionth of a second.History of the Intellectual Development of Europe, Volume II (of 2)
John William Draper
Thus, to trace it, the autopsy doctors would have to find, separate or segregate a billionth bit of the mass under observation.
- one thousand million: it is written as 1 000 000 000 or 10 9
- (formerly, in Britain) one million million: it is written as 1 000 000 000 000 or 10 12
- (often plural) any exceptionally large number
- (preceded by a or a cardinal number)
- amounting to a billionit seems like a billion years ago
- (as pronoun)we have a billion here
Word Origin and History for billionth
1680s, from French billion (originally byllion in Chuquet's unpublished "Le Triparty en la Science des Nombres," 1484; copied by De la Roche, 1520), from bi- "two" (see bi-) + (m)illion. A million million in Britain and Germany (numeration by groups of sixes), which was the original sense; subsequently altered in French to "a thousand million" (numeration by groups of threes) and picked up in that form in U.S., "due in part to French influence after the Revolutionary War" [David E. Smith, "History of Mathematics," 1925]. France then reverted to the original meaning in 1948. British usage is truer to the etymology, but U.S. sense is said to be increasingly common there in technical writing.